Air flow passage for a vacuum cleaner

ABSTRACT

A vacuum cleaner is provided having improved pressure loss characteristics. A fluid supply conduit in flow communication with an inlet to a cyclone is integrally formed as part of a cyclone bin. The present invention may be adapted for use with cyclonic separation devices of all types, including single- and multi-stage cyclonic separators.

The application is a continuation of application Ser. No. 11/56,0115filed on Nov. 15, 2006 (which is pending), which is a continuation ofapplication Ser. No. 11/114,237 filed on Apr. 26, 2005 (which isabandoned), which is a continuation of application Ser. No. 10/816,840,filed on Apr. 5, 2004, now U.S. Pat. No. 6,902,596, which is acontinuation of application Ser. No. 10/322,451, filed on Dec. 19, 2002now U.S. Pat. No. 6,736,873, which is a continuation of application Ser.No. 10/188,412, filed on Jul. 8, 2002 now U.S. Pat. No. 6,599,340 is acontinuation of PCT/CA00/00016 filed on Jan. 7, 2000, which is acontinuation-in-part of application Ser. No. 09/227,534, filed Jan. 8,1999 and which has issued as U.S. Pat. No. 6,141,826, and is adivisional of application Ser. No. 09/480,168, filed on Jan. 10, 2000and which has issued as U.S. Pat. No. 6,391,095.

FIELD OF THE INVENTION

The present invention relates generally to cyclonic separators. In oneparticular application, the invention relates to a vacuum cleaner whichuses the cyclonic separation of dirt from an air flow as the primarydirt separation mechanism.

BACKGROUND OF THE INVENTION

The use of a cyclone, or multiple cyclones connected in parallel orseries, has long been known to be advantageous in the separation ofparticulate matter from a fluid stream. Typically, a relatively highspeed fluid stream is introduced tangentially to a generally cylindricalor frusto-conical container, wherein the dirty air stream is acceleratedaround the inner periphery of the container. The centrifugalacceleration caused by the travel of the fluid in a cyclonic streamthrough the cyclone causes the particulate matter to be disentrainedfrom the fluid flow and, e.g., to collect at the bottom of thecontainer. A fluid outlet is provided for the extraction of the fluidfrom the centre of the top of the cyclone container, as is well known inthe art.

A typical flow path in a cyclone separator is as follows. Fluid to betreated is introduced tangentially at a fluid inlet located at the upperend of the cyclone container (if the cyclone container is verticallydisposed). The fluid stream rotates around the inner surface of thecyclone container, and spirals generally downwardly around the innersurface. At the bottom end of the cyclone container the fluid streamtravels radially inwardly, generally along the bottom of the containerand then turns upwardly and proceeds vertically up and out of thecyclone container. The particulate matter separating action of thecyclonic flow occurs substantially around the inner surface. Once theair moves inwardly to the centre of the container, and upwardly therethrough, there is little or no dirt separation achieved.

Various types of vacuum cleaners are traditionally produced. Theseinclude built in vacuum cleaners, canister vacuum cleaners and uprightvacuum cleaners. Upright vacuum cleaners have a ground engaging portion(a cleaning head) and an upwardly extending or main body portion. Theground engaging portion typically has wheels for movement of thecleaning head across a floor and a suction inlet for the intake of dirtyair into the vacuum cleaner. The upwardly extending portion comprisesthe filter means for removing dirt which is entrained in the air. Theupwardly extending portion generally has a handle for guiding the vacuumcleaner across the floor.

Traditionally in upright vacuum cleaners, the motor to draw the dirtyair through the vacuum cleaner is positioned in the ground engaging headand the upward extending portion is pivotally mounted to the upperportion of the ground engaging member at a position adjacent the motor.

The advantages of cyclonic separation have been combined with an uprightvacuum cleaner to provide a household cyclonic vacuum cleaner, as shownin U.S. Pat. No. 4,593,429 to Dyson. As shown in FIG. 1, this vacuumcleaner 10 essentially comprises a large, outer cylindrical cyclone 12,with an inner cyclone 14 nested therein, which is mounted on afloor-cleaning head and provided with a push handle for convenientmovement of the unit. A motor, located in the floor cleaning head, drawsair through the cleaning head and into an intake conduit 16, whichdelivers air to the dirty air inlet 18 of the outer cyclone container12. From the outer cyclone the air flows into inner, nested dustseparating cyclone 14, and from there, continues on through the vacuummotor, which is positioned in the ground engaging member, to a clean airexhaust port.

The air intake conduit 16 connects the floor cleaning head and the dirtyair inlet in air flow communication. Air intake conduit 16 extendsupwardly along the outside of outer cyclone container 12 generallyparallel to the longitudinal axis of the cyclones 12, 14. At a positionadjacent air inlet 18 to outer cyclone 12, air intake conduit 16 bends90° twice to travel inwardly and to provide a tangential air flow to airinlet 18 of outer cyclone container 12.

In use, air intake conduit 16 may become blocked. If the blockage occursat a midpoint of the conduit, it may be difficult to clear the blockage.While a clean out port may be provided, the port may not be located nearwhere the blockage occurs. Further, the addition of a port increases thecost and complexity of the manufacture of the product.

A bend in a conduit for a fluid causes a turbulent pressure loss in theconduit as the fluid travels through the bend in the conduit and thegreater the sharpness of the bend, the greater the pressure loss. Thepressure loss in the air flow decreases the amount of suction which canbe generated at the cleaning head of the vacuum cleaner for any givenmotor in the vacuum cleaner and therefore the efficiency of the vacuumcleaner.

SUMMARY OF THE INVENTION

In accordance with the instant invention, there is provided a vacuumcleaner having a source of dirty air to be treated and a housing, thevacuum cleaner comprising a cyclone bin removable from the housing andhaving a bottom, a wall having an inner surface and a cyclone axis; afluid inlet to the cyclone bin; and, a fluid supply conduit extendingalong the length of the cyclone bin from the bottom to the fluid inletand communicating with the source of dirty air to be treated and withthe fluid inlet, the fluid supply conduit is removable with the cyclonebin from the housing.

In accordance with the instant invention, there is also provided avacuum cleaner comprising cleaning head means for cleaning a surface;cyclone separation means having a cyclone axis and a bin having a wall,the wall having an inner surface; fluid inlet means for introducingfluid to the cyclone separation means; and, fluid supply conduit meanscommunicating with the cleaning head means and with the fluid inletmeans when the vacuum cleaner is in use, the fluid supply conduit meansextending through the cyclone separation means, the fluid supply conduitis removable with the cyclone separation means from the housing.

In accordance with the instant invention, there is also provided amethod comprising providing a fluid having a first element and a secondelement; conveying the fluid in a conduit longitudinally through acyclone having a cyclone bin, a cyclone axis and an inner longitudinallyextending surface, the cyclone bin removably mounted in a housing andthe conduit removable with the cyclone bin from the housing; and,passing the fluid through the cyclone to remove at least a portion ofthe first element from the fluid and obtaining at least one treatedstream having a reduced concentration of the first element.

In accordance with the instant invention, there is also provided avacuum cleaner having a source of dirty air to be treated and a housing,the cyclonic separator comprising a cyclone removably mounted in thehousing and having a bottom, a fluid inlet, a wall having an innersurface and a longitudinally extending axis; and a fluid supply conduitextending along the length of the cyclone from the bottom to the fluidinlet, the fluid supply conduit conveying the dirty air substantiallyaxially to the fluid inlet, the fluid supply conduit communicating withthe source of dirty air when the cyclonic separator is in use, the fluidinlet redirecting the dirty air from an axial flow to a tangential flowand the fluid inlet is positioned within the cyclone.

The configuration of the air intake conduit according to the presentinvention advantageously permits a substantial reduction in the backpressure caused by the air flow conduit which conveys the dirty airstream to the cyclone separation means. This reduction in pressure lossin the intake conduit may be used to improve the overall performance ofthe cyclone separation device. For example, a deeper vacuum may be drawnat the air intake of the cleaning head or other vacuuming device for agiven vacuum motor size. Conversely, using the air flow path of theinstant invention, the motor size may be reduced without a reduction incleaning efficiency, thereby permitting a comparable vacuum cleaner tobe provided at lesser cost.

In one embodiment, the fluid supply conduit extends through a centralportion of the cyclone. The fluid supply conduit preferably extendscoaxially with the axis of the cyclone and the fluid inlet preferablyextends outwardly to the inner surface.

In another embodiment, the fluid inlet includes a curved portion withoutany 90° elbows.

In another embodiment, the fluid inlet comprises at least a portion thatextends in a continuous curve.

In another embodiment, the fluid inlet is curved in a first directiontowards the inner surface of the wall and is curved in a seconddirection to introduce the dirty air tangentially to the cyclone. Thefluid inlet may be curved so as to sequentially redirect the air in thefirst direction and then the second direction. Preferably, the fluidinlet is curved so as to simultaneously redirect the air in the firstdirection and the second direction.

In another embodiment, the fluid inlet has a curved portion to impart arate of change of direction in the fluid travelling there through in twoaxis simultaneously.

In another embodiment, the fluid supply conduit extends longitudinallythrough the cyclone and the cyclone is removably mounted in the housing.

In another embodiment, the downstream end of the fluid inlet extendssubstantially horizontally.

In another embodiment, the downstream end of the fluid inlet extendstowards the bottom of the cyclone.

In another embodiment, the downstream end of the fluid inlet extendstowards the bottom of the cyclone at an angle of up to 10° from a planeperpendicular to the axis.

In another embodiment, the cyclone has an outlet having a wall and aportion of the fluid inlet is nested within the outlet and a portion ofthe fluid inlet is positioned exterior the outlet.

In accordance with the instant invention, there is also provided acyclonic separator having a source of fluid to be treated, the cyclonicseparator comprising a cyclone having a bottom, a fluid inlet, a wallhaving an inner surface and a longitudinally extending axis, the fluidinlet having an upstream end and a downstream end; and, a fluid supplyconduit extending substantially along the axis of the cyclone from thebottom to the upstream end of the fluid inlet, the fluid supply conduitcommunicating with the source of fluid when the cyclonic separator is inuse, the fluid inlet is curved in a first direction towards the wall andis curved in a second direction to introduce the fluid tangentially tothe cyclone.

In one embodiment, the cyclone has an outlet having a wall and at leasta portion of the fluid inlet is nested within the outlet and extendsthrough the wall of the outlet.

In another embodiment, the inlet comprises a duct extending from pointS1 to point S2 and comprises a space curve around which the conduit isformed wherein the gradient of the space curve has at least two non-zerocomponents which vary along the arc length of the curve. Preferably, thespace curve comprises a helical segment.

Preferably, the helical segment is defined byS(t)=(G)*(cos(t), sin(t),t).(x,y,z)

whereby

(a) the gradient of the space curve has at least two non-zero componentswhich vary along the arc length of the curve

(b) t1<t<t2

(c) S(t1) is equal to S1; and,

(d) S(t2) is equal to S2.

Preferably, the duct comprises an envelope formed by a radius r out fromthe central space curve which is itself formed about a constructioncylinder having a radius R and an axis wherein the conduit the duct hasa radius r where r<R and the space curve at S1 smoothly becomes astraight line coincident with the axis of the construction cylinder.

Preferably, the space curve at S2 smoothly becomes a straight linecoincident with the derivative of S(t) at point S2 with respect to theparameter t.

In accordance with the instant invention, there is also provided acyclonic separator having a source of fluid to be treated, the cyclonicseparator comprising cyclone separation means having a longitudinallyextending axis and a length; fluid supply conduit means extendingsubstantially along the length of the cyclone separation means, thefluid supply conduit means communicating with the source of fluid whenthe cyclonic separator is in use; and, fluid inlet means for redirectingthe fluid from a substantially axial flow for introduction tangentiallyto the cyclone means without any 90° elbows.

In another embodiment, the cyclonic separator further comprises housingmeans for removably receiving the cyclonic separation means wherein thecyclone separation means has outlet means having a wall and a portionwhich is removable with the cyclone separation means from the housingmeans and the fluid inlet means passes through the wall of the outletmeans.

In accordance with the instant invention, there is also provided amethod comprising providing a fluid having a first element and a secondelement; conveying the fluid in a conduit longitudinally through acyclone having a longitudinal axis and a longitudinally extendingsurface; conveying the fluid in a conduit laterally to thelongitudinally extending surface; and, introducing the fluid into thecyclone and passing the fluid through the cyclone to remove at least aportion of the first element from the fluid and obtain at least onetreated stream having a reduced concentration of the first element.

In one embodiment, the method further comprises conveying the fluidcentrally through the cyclone.

In another embodiment, the method further comprises conveying the fluidaround at least a portion of the longitudinal axis of the cyclone as thefluid passes outwardly from the central portion.

In another embodiment, the method further comprises providingcentrifugal acceleration to the fluid as it passes outwardly from thecentral portion.

In accordance with the instant invention, there is also provided a fluidsupply conduit comprising a curved portion to impart a rate of change ofdirection in the fluid travelling there through in two axissimultaneously.

In accordance with the instant invention, there is also provided amethod comprising providing a fluid having a first element and a secondelement; conveying the fluid to a cyclone; introducing the fluid throughan inlet to the cyclone to impart a rate of change of direction in thefluid travelling there through in two axis simultaneously; and passingthe fluid through the cyclone to remove at least a portion of the firstelement from the fluid and obtain at least one treated stream having areduced concentration of the first element.

In accordance with the instant invention, there is also provided anupright vacuum cleaner comprising a cleaning head for cleaning asurface; an upper body portion mounted on the cleaning head, the upperportion having a longitudinally extending axis and comprising at leastone cyclone having an air entry port; and a motor positioned above theat least one cyclone and in air flow communication with the at least onecyclone.

In accordance with the instant invention, there is also provided anupright vacuum cleaner comprising a cleaning head for cleaning a surfacehaving a forward portion and two spaced apart rear portions extendingrearwardly from the forward portion; an upper body portion mounted onthe cleaning head, the upper portion having a longitudinally extendingaxis and at least one cyclone having an air entry port, the upper bodyportion mounted on the cleaning head at a position forward of the spacedapart rear portions, the spaced apart rear portions defining on openspace there between sized for receiving the upper body portion therebetween when the upper body portion is in the lowered storage position.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show moreclearly how it may be carried into effect, reference will now be made byway of example to the accompanying drawing which show a preferredembodiment of the present invention, in which:

FIG. 1 is a cross-sectional side elevation of an upright cyclonic vacuumcleaner with an air intake conduit according to the prior art;

FIG. 2 is a cross-section along line 2-2 in FIG. 4 of an uprightcyclonic vacuum cleaner with an air intake conduit according to thepresent invention;

FIG. 3 is a perspective view of an upright vacuum cleaner according tothe instant invention;

FIG. 3 a is a cross-section along line 3-3 in FIG. 3 of an alternatepreferred embodiment of an upright cyclonic vacuum cleaner with an airintake conduit according to the present invention;

FIG. 4 is a cross-section along line 4-4 in FIG. 2;

FIG. 5 is a cross-section along line 4-4 in FIG. 2 of an alternatepreferred embodiment;

FIG. 6 is a cross-section along line 6-6 in FIG. 7 of a furtheralternate preferred embodiment of the instant invention;

FIG. 7 is a cross-section along the line 7-7 in FIG. 6;

FIG. 8 is a cross-section along line 8-8 in FIG. 9 of a furtheralternate preferred embodiment of the instant invention;

FIG. 9 is a cross-section along the line 9-9 in FIG. 8;

FIG. 10 is a cross-section along line 10-10 in FIG. 11 of a furtheralternate preferred embodiment of the instant invention;

FIG. 11 is a cross-section along the line 11-11 in FIG. 10;

FIG. 12 is a cross-section along line 12-12 in FIG. 13 of a furtheralternate preferred embodiment of the instant invention;

FIG. 13 is a cross-section along the line 13-13 in FIG. 12;

FIG. 14 is a cross-section along line 14-14 in FIG. 15 of a furtheralternate preferred embodiment of the instant invention;

FIG. 15 is a cross-section along the line 15-15 in FIG. 14;

FIG. 16 is a cross-section along line 16-16 in FIG. 17 of a furtheralternate preferred embodiment of the instant invention;

FIG. 17 is a cross-section along the line 17-17 in FIG. 16;

FIG. 18 is a cross-section along line 18-18 in FIG. 19 of a furtheralternate preferred embodiment of the instant invention;

FIG. 19 is a cross-section along the line 19-19 in FIG. 18;

FIG. 20 is a cross-section along line 20-20 in FIG. 21 of a furtheralternate preferred embodiment of the instant invention and FIG. 21 is across-section along the line 21-21 in FIG. 20;

FIG. 20 a is a cross-section along line 20-20 in FIG. 21 a of a furtheralternate preferred embodiment of the instant invention and FIG. 21 a isa cross-section along the line 21-21 in FIG. 20 a;

FIG. 22 is an enlargement of the upper portion of the cyclone chamberwhen positioned in the housing of the vacuum cleaner of FIG. 3;

FIG. 23 is an exploded view of the cyclone chamber and housing of thevacuum cleaner of FIG. 3;

FIG. 24 is a perspective view of the cyclone chamber when removed fromthe housing of the vacuum cleaner of FIG. 3;

FIG. 25 is an exploded view of the cyclone chamber of FIG. 24;

FIG. 26 is an enlargement of the upper portion of the downstream portionof the air supply conduit of the vacuum cleaner of FIG. 3;

FIG. 27 is a top plan view of the upper portion of the downstreamportion of the air supply conduit of FIG. 26.

FIG. 28 is an alternate embodiment of the upper portion of thedownstream portion of the air supply conduit of FIG. 26;

FIG. 29 is a further alternate embodiment of the upper portion of thedownstream portion of the air supply conduit FIG. 26; and,

FIGS. 30 and 30 a are an embodiment demonstrating the construction of athree dimensional curve according to another aspect of the instantinvention.

DETAILED DESCRIPTION OF THE INVENTION

The following description of improvements in cyclone separators isdescribed in their use with a vacuum cleaner and in particular anupright vacuum cleaner. It will be appreciated that the improvements incyclonic separators described herein may be used with canister vacuumcleaners, central vacuum cleaners, back pack vacuum cleaners as well ascyclonic separation devices of any sort, including industrial dustcollection systems and liquid/liquid, liquid/gas and gas/gas separationsystems. For example, they may be used with single or multiple stage offiltration assemblies, and may even be utilized where nested serialcyclones are employed.

An upright cyclonic vacuum 20 according to the present invention isshown in the FIGS. 2, 3 and 3 a. In the embodiment of FIG. 2, the motoris positioned in the cleaning head and the cleaned air is conveyed tothe motor for cooling the motor. According to the embodiment of FIGS. 3and 3 a, the motor is positioned in the upper body portion of the vacuumcleaner. If the vacuum cleaner is a canister vacuum cleaner or a centralvacuum cleaner, then the cleaning head may be in air flow communicationwith the cyclone chamber via a flexible hose.

Referring to the embodiment of FIG. 2, a floor cleaning head 22, whichmay be any known in the art, is provided at the lower end of cleaner 20.Head 22 comprises a vacuum fan motor 24, a bottom 25 and a transverselyextending, floor-contacting rotating brush member 26 which is connectedfor rotation to a shaft (not shown) within an opening 27 in bottom 35.Motor 24 provides motive force to rotate brush 26 by means of, forexample, a belt (not shown). Mounted on the cleaning head is a housinghaving a cyclonic dust separation unit, indicated generally at 28.Cyclonic unit 28 may comprise any type of dirt separation cyclone knownin the art, e.g. cylindrical or frusto-conical, and may comprise asingle stage cyclone or multiple stage cyclone (either in series and/orin parallel). Clean air outlet 40 is in air communication with motor 24via air exit conduit 41. Upper end 34 of container 30 is sealed, such asby an upper panel 35. A handle 42 and wheels 44 may be provided oncleaner 20 to facilitate movement of the unit for cleaning of a floor,and the like.

Referring to FIGS. 3, 3 a, 10 and 11, in this embodiment vacuum cleaner20 has a floor cleaning head 22, means for moving cleaning head 22across a floor (e.g. wheels 44 which may comprise rear wheels or frontand rear wheels), a housing 60 rotatably attached to cleaner head 22,and a handle 42 for moving cleaner 20 across the floor. In thisembodiment, cleaning head 22 comprises a forward portion 21 and two rearportions 23 extending rearwardly from the forward portion 21. Rearportions 23 are spaced apart and define a space 118 there between. Avalve means 68 (e.g. a rotatable valve as is known in the art) isprovided in cleaning head 22 so as to connect downstream portion 50 ofair conduit 46 in air flow communication with upstream portion 48 of airconduit 46 when housing 60 is rotated rearwardly in the direction ofarrow B in which position vacuum cleaner 20 is configured for use forcleaning a floor. Housing 60 houses at least one cyclone separator. Inthis embodiment, cyclonic separator unit 28 uses one cyclone separator,namely container or cyclone bin 30. It will be appreciated that a secondstage filtration means, which may comprise a single stage cyclone ormultiple stage cyclone (either in series and/or in parallel), may bepositioned downstream from container 30 such as in cavity 62. If thesecond stage filtration means comprises a plurality of cyclones, thenthe second stage cyclones are preferably in parallel. The treated airtravels upwardly from clean air outlet 40 to motor 24 either directly orthrough a secondary filtration stage which may optionally be positionedin cavity 62. The cleaned air may then exit housing 60 via outlet 116 orit may first optionally pass through chamber 144, which may contain afurther filtration means (e.g. a HEPA™ filter).

Cyclonic unit 28 comprises at least a first cyclone container or bin 30having an air inlet 56, preferably at upper end 34 thereof, adapted forproviding an air flow tangentially to an inner dirt rotation surface 36of container 30. Air inlet 56 may be configured to provide an axial flowof air to container 30 and opening 32 at the downstream end of air inlet56 may have vanes to impart cyclonic flow to the air stream. Preferably,inlet 56 is configured to introduce the air tangentially to container30. Container 30 also has a dirt collection surface or bottom 38 and aclean air outlet 40.

In the embodiment of FIG. 2, conduit 41 may be positioned exterior tocontainer 30. In a preferred embodiment, conduit 41 is provided on outersurface 37 of container 30 as shown in FIGS. 4, 18 and 20. In such anembodiment, conduit 41 is preferably provided as a one piece assemblywith container 30 (e.g. it may be made integrally therewith or it may bemade separately and then mounted to outer surface 37 such as by beingwelded thereto or by being removably attached thereto by mechanicallocking means provided on outer surface 37) so that conduit 41 isremovable from housing 60 automatically with container 30. Alternately,conduit 41 may be positioned within container 30 (either centrally asshown in FIG. 6, or adjacent surface 36 as shown in FIGS. 8, 12, 14 and16). Further, the treated air may optionally exit the vacuum cleaner atany desired location if it is not required to cool the motor.

The air flow path through cleaner 20 commences with an air supplyconduit 46 having an upstream portion 48 and a downstream portion 50.Upstream portion 48 is provided in head 22 and has a first end 52positioned adjacent brush member 26 or the like for receiving the dirtladen air and a distal second end 54. Downstream portion 50 has aupstream end 64 which is positioned in air flow communication withsecond end 54 and a downstream end 66. Preferably ends 54 and 64 aresubstantially sealed together to prevent air and dirt leaking therefrom.

In one embodiment, upstream and downstream portions 48, 50 may comprisea single member (whether integrally formed or connected together to forma continuous flow path). In such a case, a separated dirt collectionmeans may be positioned below container 30 or portions 48, 50 may beflexible so as to allow cyclone container 30 to be removed from housing60 and emptied. In another embodiment, upstream and downstream portions48, 50 are separate elements and downstream portion 50 is removable withcontainer 30 from housing 60 such that portions 48, 50 are in air flowcommunication when container 30 is mounted in housing 60 of vacuumcleaner 20. Thus, if a blockage develops in conduit 46, by removingcontainer 30 from housing 60 as shown in FIG. 23, portions 48 and 50 maybe individually accessed at ends 54 and 64 to clean out the blockage.

As shown in FIGS. 2, 3, 6, 8, 10, 12, 14 and 16 downstream portion 50may extend upwardly through container 30. Alternately, as shown in FIGS.18 and 20, downstream portion 50 may extend upwardly at a positionadjacent outer surface 37 of container 30. Whether downstream portion 50is provided internally or externally to container 30, by manufacturingthe vacuum cleaner so that downstream portion 50 is removable withcontainer 30 from housing 60 (i.e. in a single operation), access isprovided at ends 54 and 64 in case of a blockage. Accordingly, multipleaccess ports are effectively provided as part of the construction of thevacuum cleaner. It will be appreciated that downstream portion 50 may bemanufactured as part of container 30 (such as by moulding it integrallytherewith). Alternately, it may be separately manufactured (such as byextrusion) and subsequently affixed to container 30 by any means knownin the art (e.g. by welding, engagement of male and female engagementmembers of the like). In either event, downstream portion 50 andcontainer 30 are a one piece assembly so that when container 30 isremoved from housing 60, downstream portion 50 is automatically removedat the same time.

Downstream portion 50 may enter container 30 at any point (e.g. via aside wall) but preferably enters through bottom 38. Further downstreamportion 50 preferably extends generally upwardly through the centralportion of container 30 which comprises the area occupied by thevertical return path of the fluid as it travels from bottom 38 to outlet40. As shown in FIGS. 2 and 3 a, downstream portion 50 preferablyextends coaxially with the longitudinal axis A of container 30, however,it may be positioned off centre either internal of container 30 (see forexample FIG. 12) or external of container 30 (see for example FIGS. 18and 20). Since downstream portion and container 30 define a completecontainer for the separated dirt, an advantage of this invention isthat, when it is desired to empty container 30, a complete dirtcontainer is removed from the vacuum cleaner in a single step operation.

Downstream portion 50 is preferably positioned at any location withincontainer 30 where it does not unduly interfere with the cyclonic flowof air within container 30. For this reason, if downstream portion 50 ispositioned within container 30, it is preferably centrally located incontainer 30. In particular, in a cyclone, the air travels generally inan annular band adjacent surface 36 of container 30. The air travelsgenerally downwardly until it reaches a position towards bottom 38 ofcontainer 30 at which point the air travels upwardly through the centralportion of cyclone container 30. In a most preferred embodiment of thisinvention, downstream portion 50 is positioned within this centralportion of container 30 through which this up flow of air passes.

As shown in FIGS. 12, 14 and 16, downstream portion 50 may be positionedadjacent sidewall 36. In such cases, downstream portion 50 is preferablyconstructed so as to minimize its interference with the flow of airaround surface 36. For example, downstream portion 50 may be constructedwith rounded surfaces so as to direct the flow of air around downstreamportion 50. Further, downstream portion 50 need not be circular in shapebut may be elliptical or of other constructions wherein it has acircumferential width (i.e. around inner surface 36) which issubstantially greater than its radial width in a direction transversethereto (i.e. radially inwardly). Thus, downstream portion 50 wouldextend only slightly into container 30 and would not substantiallyinterfere with the cyclonic flow of air in container 30. If conduit 41is positioned adjacent inner surface 36, it is also preferably soshaped. It will be appreciated than downstream portion 50 and conduit 41may be positioned on opposed portions of inner surface 36 (see FIG. 12)or at any other location, such as adjacent each other (see FIG. 14).

In another embodiment, downstream portion 50 and outlet 40 may be nestedone within the other. For example, as shown in FIGS. 6 and 7, downstreamportion 50 may be positioned within, and preferably co-axially within,conduit 41. Alternately, conduit 41 may be positioned within, andpreferably co-axially within, downstream portion 50 (see FIGS. 20 a and21 a). As shown in FIG. 16, conduits 41 and 50 may be provided in anested relationship adjacent surface 36. It will also be appreciatedthat conduits 41 and 50 may be positioned adjacent each other, forexample, adjacent inner surface 36 as shown in FIG. 14, or within thecentral portion of container 30 (not shown). Further, they may be nestedwithin each other or positioned adjacent each other when locatedadjacent the exterior of container 30 as shown in FIGS. 18 and 20.

Air inlet 56 is positioned at the upper end of downstream portion 50.Opening 32 is positioned at the distal end of air inlet 56 from end 66of downstream portion 50. Air inlet 56 defines the exit portion of theair supply conduit extending longitudinally with the cyclone and mayextend along any desired path from downstream portion 50 to opening 32.Preferably, air inlet 56 is wholly positioned within container 30 (e.g.it does not exit or enter the container 30 through upper end 34).

Air inlet 56 may extend at a right angle to downstream portion 50 asshown in FIG. 2. Further, it may extend in a straight line to opening 32as shown in FIG. 4. It will be appreciated that opening 32 may be anyinlet known in the cyclonic art to introduce air tangentially into acyclone and it may be positioned at any point along the longitudinallength of container 30 as is known in the cyclonic art.

Typically vacuum cleaners utilize 90° elbows to redirect an air flowfrom one plane to a plane at right angles thereto. In particular, theair travels in a first direction when it enters an elbow and then, whenit encounters the wall of the elbow, it is directed to travel in asecond direction which is at 90° to its first line of travel. The axisof flow of the inlet and the outlet from a 90° elbow are at right anglesand exist in a single plane. In order to change the direction of travelof the air into another direction, a second 90° elbow is used. With acyclone inlet, in is generally necessary to redirect an air flow throughtwo planes (i.e. an axial flow to a lateral flow and the lateral flow toa tangential flow). A first 90° elbow is used to redirect the air froman axial flow to a lateral flow into a cyclone and a second 90° elbow isused to redirect the lateral flow into a tangential flow.

In one preferred embodiment, air inlet 56 is constructed so as not tohave any 90° elbows. Instead, air inlet 56 includes curved portions forredirecting the air so as to impart circular momentum to the dirty airas it travels there through (as shown in FIG. 5) and/or, air inlet 56includes a curved portion for redirecting the air from an axial flow toflow outwardly to inlet 32 (as shown in FIG. 26). By constructing thesupply conduit in this manner, 90° elbows are not required to redirectthe dirty air to flow outwardly or to redirect the dirty air to entercontainer 30 tangentially. In a typical application, replacing a 90°elbow with a gradual curved path to redirect the dirty air results in aabout a 5 to 10% reduction in the loss of suction as the air travelsthrough the vacuum cleaner. Thus, a smaller motor may be incorporatedinto the vacuum cleaner to obtain the same pressure at opening 32 or thesuction at end 52 may be increased if the same motor is used.

Referring to FIG. 3 a, it will be appreciated that the dirty airtravelling in downstream portion 50 must travel outwardly to inlet 56.In the preferred embodiment of FIG. 3 a, air inlet 56 curves gently fromdownstream end 66 of downstream portion 50 so as to travel outwardly andgenerally radially towards opening 32. More preferably, the change indirection of the dirty air from generally vertical to generallyhorizontal and from generally horizontal to generally tangential occursso as to reduce the pressure drop during its travel from downstreamportion 50 to container 30. Accordingly, the curved portion of inlet 56is curved to direct the dirty air from travelling generally verticallyto generally tangentially. This may be achieved by gradually redirectingthe air from a generally vertical flow (assuming the axis A of thecyclone is vertical) to a generally horizontal flow and then from thegenerally horizontal flow to a generally tangential flow or alternatelyby gradually redirecting the air from a generally vertical flow(assuming the axis A of the cyclone is vertical) to a generallytangential flow and then from the generally tangential flow to agenerally horizontal flow. These redirections may occur sequentially (ineither order) or, preferably, at least a portion of these redirectionsoccurs simultaneously to impart a rate of change of direction in thefluid travelling there through in two axis simultaneously. Further thecurved portion of the inlet may be a continuous curve so as tocontinually impart changes to the direction of the dirty air travellingthere through or it may have a straight portion incorporated therein.Preferably, it defines a continuously curved member.

In accordance with a preferred embodiment of this invention, threedimensional inlet 56 can be considered as an envelope built around aspace time. Every point on the space curve is a centre of the crosssection of the envelope built around it. The curve can be defined byS(x,y,z). The curve joins together two points in space not by a straightline but by means of a curve or, preferably a helical curve or otherrelated curve wherein the gradient of the space curve has at least twonon-zero components which vary along the arc length of the curve.

Referring to FIGS. 30 and 30 a, inlet 56 is a duct or conduit comprisingan envelope formed by a radius r out from a central space curve 120having an upstream end 122 and a downstream end 124 and which is itselfformed about an imaginary cylinder 126. This cylinder is imaginary inthe sense that it is used for the purpose of mathematically constructingthe conduit. The central space curve 120 begins and ends at the pointsS1 and S2. The imaginary (construction) cylinder 126 has a radius R.Radii r and R may themselves be varied as functions of (x,y,z) providedthat the duct has a radius r where r<R functions. The helical segment ofthe space curve 120 around which the duct is formed can therefore bedefined by S(t)=(G)*(cos(t), sin(t),t).(x,y,z) such that the gradient ofthe space curve 120 has at least two non-zero components which varyalong the arc length of the curve 120. Furthermore, t1≦t≦t2 and S(t1) isequal to S1 and S(t2) is equal to S2. The space curve at S1 smoothlybecomes a straight line coincident with the construction cylinder's axisC of the construction cylinder. The space curve 120 at S2 smoothlybecomes a straight line coincident with the derivative of S(t) at pointS2 with respect to the parameter t.

It will be appreciated that this duct may be used with any fluid stream(liquid or gaseous) and need not be used in association with a cycloneseparator. In particular, the three dimensional duct may be usedwhenever it is desired to alter the direction of travel of a fluidthrough more than one plane. Thus, the three dimensional duct may beused with a fluid stream that has entrained particulate matter such as adirty air flow stream to a vacuum cleaner (cyclonic or otherwise) orwith a fluid stream which does not contain any material to be separatedbut is flowing through a system.

Centrally located in upper end 34 of container 30 is a clean air outlet40 for permitting withdrawal of air from container 30, as will bedescribed below. From clean air outlet 40, the air flow may proceed, ifdesired, to a second stage of filtration, such as a second cyclone orother filtration means (not shown). Subsequently, it may be in air flowcommunication with vacuum fan motor 24 via air exit conduit 41. Head 22has an exhaust port (not shown) for expelling clean air to theenvironment.

In operation, the vacuum fan motor 24 is activated to induce an air flowthrough cleaner 20. The air flow causes a partial vacuum to form at end52. Air, and entrained dirt, is drawn into upstream portion 48, with theaid of brush member 26. The dirty air flow moves vertically indownstream portion 50 to opening 32 in air inlet 56 and is introducedtangentially to container 30. The airflow is then accelerated arounddirt rotation surface 36, and proceeds generally downwardly along andaround dirt rotation surface 36 until it reaches a position towardsbottom 38 of container 30, at which point the air flow travels upwardlythrough the central portion of cyclone container 30. Wall 58 may providean extension of outlet 40 in container 30. Wall 58 assists in preventingthe treated air travelling upwardly to outlet 40 from mixing with thedirty air which is introduced into container 30 via inlet 56.

As can be seen by a comparison of intake conduits 16 and 46, of cleaner10 and cleaner 20 respectively, the reduction of bends in the airconduit of the present invention beneficially results in a significantreduction in the turbulent pressure loss in the intake conduit, therebymarkedly improving the efficiency of the cyclonic separation device as awhole.

The presence of downstream portion 50 extending through the centre ofcontainer 30 interferes minimally with the cyclonic action of the airflow within container 30. Thus the presence of downstream portion 50does not significantly effect the efficiency of the cyclone.

The removability of container 30 from housing 60 of vacuum cleaner 20 ismore particularly shown by reference to FIGS. 3 a, 22 and 23. Housing 60comprises a base 72, an upper portion 76 and struts 74 which extendbetween base 72 and upper portion of housing 76 so as to define a cavitywithin which container 30 is received. It will be appreciated thathousing 60 may be of any configuration which provides an area in whichbin 30 may be received. For example, it will be appreciated that ifvacuum cleaner 20 is a canister vacuum cleaner, that container 30 mayextend horizontally, or at any inclined angle to the horizontal andhousing 60 may be of any shape within which container 30 may bereceived.

Container 30 may be lockingly received in housing 60 by any means knownin the art. In the preferred embodiment, container 30 is provided with alid 70 which has a recess 80 provided in handle 78 thereof. Container 30and lid 70 comprise a cyclone chamber which is removable received inhousing 60. Lower surface 102 of upper portion 76 of housing 60 isprovided with a protrusion 92 which is receivable in recess 80. Bymoving handle 78 downwardly to the position shown in dotted outline inFIG. 22, protrusion 82 is removed from recess 80 allowing bin 30 to beremoved from base 72 as is shown in FIG. 23. Recess 80 and protrusion 82are a male and female detent means. It will be appreciated that othermale and female detent means or the like which are known in the art maybe utilized so that container 30 may be releasably lockingly received inhousing 60.

In the embodiment of FIG. 3 a, the cleaned air travels upwardly outabove container 30. Accordingly, lid 78 is provided with an uppersurface 84. Cylindrical wall 58 extends downwardly from upper surface84. The intersection of upper surface 84 and wall 58 describes opening40 which is the clean air outlet.

As can be seen in FIG. 23, downstream portion 50 of air supply conduit46 is removed from housing 60 with container 30. In this embodiment,downstream portion 50 comprises a centre feed tube. Upstream end 64 isremovable from downstream end 54. Sealing means, such as O-ring 104 maybe provided to join ends 54 and 64 in air flow communication when bin 30is replaced in housing 60 so as to prevent any leak or any substantialleak where ends 54 and 64 meet.

Lid 70 may be releasably mounted to container 30 by any means known inthe art. Referring to FIG. 25, lower end 86 of lid 70 is provided with arecessed surface 90 having two protrusions 92 provided therein. Upperend 88 of container 30 is provided with bayonet mounts 94 for receivingprotrusions 92. Accordingly, once container 30 is removed from housing60, lid 70 is rotated slightly counter clockwise so as to release thebayonet mount whereby lid 70 may then be lifted from container 30 thusallowing container 30 to be emptied.

As further exemplified in FIG. 25, in the preferred embodiment, airinlet 56 is removed with lid 70 from container 30. The construction ofair inlet 56 is more particularly shown in FIGS. 26-29. Referring to thepreferred embodiment of FIG. 26, it can be seen that air inlet 56comprises a three dimensionally curved member which curves firstupwardly and outwardly from centre feed tube 50 through wall 58 into theinterior of container 30 which functions as the cyclone chamber. Inlet56 then continues to curve outwardly and radially so as to provide atangential air inlet to container 30.

Downstream end 66 of centre feed tube 50 is in air flow communicationwith end 106 of air inlet 56. End 106 is provided with a means such as acollar 108 into which end 66 is received so as to join inlet 56 in airflow communication with centre feed tube 50. It will be appreciated thatany other means known in the art may be used to join centre feed tube 50in air flow communication with air inlet 56.

Referring to FIGS. 26 and 27, it can be seen that air inlet 56 has alongitudinally extending portion 110 at the end of which is the curvedinlet portion which ends at opening 32. In this embodiment, the curvedinlet portion comprises a continuous three dimensional curve from upperend 112 of longitudinally extending portion 110 through to the distalend which contains opening 32.

In a further alternate embodiment, as shown in FIG. 29, the distal endof inlet 56 may have an extension member 100 provided on the upperportion thereof. It will be appreciated that extension member 100 may beprovided either in the embodiment of FIG. 26 or in the embodiment ofFIG. 28.

Opening 32 and/or extension 100 may extend horizontally (i.e. in a planetransverse to the longitudinal axis A of container 30). In a preferredembodiment, opening 32 extends downwardly at an angle □ of about 1 toabout 10°, preferably from about 5 to about 10° from the horizontal. Inparticular, referring to FIG. 28, reference numeral 96 refers to a planewhich is at right angles to longitudinal axis A of container 30.Reference numeral 98 defines the axis of opening 32 (i.e. the endportion of curved inlet 56 which extends along axis 98).

The configuration of the air intake conduit according to the presentinvention advantageously permits a substantial reduction in the pressureloss experienced in the intake conduit without interfering with theoverall performance of the cyclone separation device. Thus, the presentinvention permits a deeper vacuum to be drawn at the intake end 52, fora given vacuum motor size. Conversely, the motor size may be reduced inconjunction with the present invention without losing vacuum power overdevices having air intake conduits according to the prior art, therebypermitting a comparable vacuum cleaner to be provided at lesser cost.

In the embodiment of FIG. 3 a, it will be appreciated that from secondend 54, the dirty air travels upwardly through the filtration stages andexits the vacuum cleaner at the top. In particular, the air travelsupwardly to air inlet 56 to cyclonic unit 28. The air then travelsupwardly from air outlet 40 to the motor and, if desired, furtherupwardly to a further filtration stage (e.g. a HEPA™ filter) which maybe positioned in chamber 114 which is provided in housing 60 above motor24. Regardless of the sequence of the filtration stages, or theirnumber, the air preferably continues to travel generally upwardly fromone stage to the next without 90° elbows being required to direct theair flow.

While the above description constitutes the preferred embodiments, itwill be appreciated that the present invention is susceptible tomodification and change without departing from the fair meaning of theproper scope of the accompanying claims.

It will be appreciated that if conduit 41 extends to a position adjacentmotor 24, then it is preferably constructed from two portions in asimilar fashion to supply conduit 46 such that the upstream portion ofconduit 41 is removable with container 30 from the vacuum cleaner and isin air flow communication with the downstream portion of conduit 41 (seefor example FIG. 6) when container 30 is reinserted into the vacuumcleaner such that the upstream and downstream portions of conduit 41provide air flow communication for the clean air to travel past themotor to provide cooling therefor.

It will be appreciated by those skilled in the art that variousadditions and modifications may be made to the instant invention and allof these are within scope of the following claims. For example, thecyclone separator may have a hopper of the like provided in one endthereof for channeling the separated particulate matter to a collectionchamber positioned external to the cyclone separator or to for otherpurposes downstream from the cyclone separator.

1. A vacuum cleaner comprising: (a) a cleaning head for cleaning asurface; (b) a fluid flow path from a dirty air inlet of the cleaninghead to a clean air outlet and including a cyclone container having alongitudinal axis, the cyclone container having a longitudinal wallhaving an outer surface and an interior volume; and (c) an air flowconduit forming a one piece assembly with the cyclone container, the airflow conduit spaced laterally from the interior volume positionedexterior to the cyclone container, extending in a longitudinal directionof the cyclone container and removable with the cyclone container fromthe vacuum cleaner, the air flow conduit forming part of the fluid flowpath through the vacuum cleaner.
 2. The vacuum cleaner of claim 1,wherein the air flow conduit is integrally formed as part of the cyclonecontainer.
 3. The vacuum cleaner of claim 1, wherein the air flowconduit is mounted to the cyclone container.
 4. The vacuum cleaner ofclaim 1, wherein the air flow conduit is positioned adjacent the outersurface of the cyclone container.
 5. The vacuum cleaner of claim 1,wherein the air flow conduit comprises an air exit conduit and thevacuum cleaner further comprises a fluid feed conduit nested within theair exit conduit.
 6. The vacuum cleaner of claim 1, wherein the air flowconduit comprises an air exit conduit and the vacuum cleaner furthercomprises a fluid feed conduit wherein the air exit conduit is nestedwithin the fluid feed conduit.
 7. The vacuum cleaner of claim 1, whereinthe air flow conduit comprises an air exit conduit.
 8. The vacuumcleaner of claim 1, wherein the air flow conduit extends along a lengthof the longitudinal wall.
 9. The vacuum cleaner of claim 1, wherein theair flow conduit is positioned adjacent the longitudinal wall.
 10. Thevacuum cleaner of claim 1, wherein the cyclone container has first andsecond longitudinally spaced apart ends and the air flow conduit ispositioned between the spaced apart ends.
 11. The vacuum cleaner ofclaim 1, wherein the cyclone container has first and secondlongitudinally spaced apart ends and the air flow conduit extendsgenerally parallel to the longitudinal axis between the spaced apartends.